Author and illustrator Alice Provensen, who, with her late husband Martin Provensen illustrated more than 40 books and won a Caldecott Medal and Caldecott Honor before starting a solo career, died on April 23. She was 99.

Alice Twitchell Provensen was born on August 14, 1918 in Chicago, to parents who were consistently supportive of her interest in art. From a young age, Provensen enjoyed reading and was fascinated by airplanes and airshows—a passion she would later discover was shared by her husband as he was growing up, also in Chicago. Provensen won a scholarship to the Art Institute of Chicago, but then transferred to the University of California at Los Angeles, where she studied for a year before moving to New York City to train at the Art Students League.

A short time later, in 1942, Provensen returned to California and began doing animation work at Walter Lantz Studios, home of the Woody Woodpecker cartoons. Following a parallel path, Martin Provensen had been working at Walt Disney Studios prior to WWII on such films as Dumbo and Fantasia, but while serving in the U.S. Navy beginning in 1942, he was assigned to create war-related training films. One such government film project brought Martin to the Universal film lot and Lantz Studios in 1943, where he met Alice. They were married in 1944 in Washington, D.C., where Alice had a position working on graphics in the Office of Strategic Services as Martin continued to work for the Navy.

In 1945, the Provensens moved to New York City and soon began illustrating books for children as a team with an assist from an artist friend, Gustaf Tenggren, who had worked at Disney and who had begun illustrating Little Golden Books titles, including The Poky Little Puppy, in 1942. Their first published title was The Fireside Book of Folksongs (Simon Schuster, 1947), for which Alice told Something About the Author they did 500 illustrations.

By 1950, the pair had embarked on a change of scenery and was traveling throughout Europe “collecting material for illustrations,” according to Provensen. Later that same year they purchased a farm near Staatsburg, N.Y.—Maple Hill Farm—and converted the barn into an art studio, where they worked together in a prolific collaboration for more than 30 years. Their illustrations have been praised as stylistic and detailed while also often conveying warmth and humor.

In an autobiographical essay for Something About the Author, Alice explained their process. “We work together on all our illustrations, much as the medieval scribes and scriveners did, passing the drawings back and forth between us, adding this or taking out that, until each is satisfied. We discard sketch after sketch until finally we obtain the effect we feel will most delight the young eye.”

In many instances, bookmaking became a true family affair, with then-preschool-age daughter Karen contributing to concept books Karen’s Curiosity and Karen’s Opposites, both published by Golden Press in 1963. The Provensens cited their daughter and their farm (and its animals and tools) as inspiration for a number of other books as well.

Among some of the Provensen’s best known works are the illustrations for A Visit to William Blake’s Inn: Poems for Innocent and Inexperienced Travelers by Nancy Willard (Harcourt, 1981), for which Willard won the 1982 Newbery Medal and the Provensens won a 1982 Caldecott Honor, and The Glorious Flight: Across the Channel with Louis Bleriot (Viking, 1983), the title that won them the 1984 Caldecott Medal.

During a 2001 interview with Leonard S. Marcus that appeared in Publishers Weekly, the Provensens recalled their delight when an antique airplane museum and flying school called the Old Rhinebeck Aerodrome had opened near their farm in the late 1950s. They attended many air shows there over the years, and when they began working on The Glorious Flight, Martin was taking flying lessons at the Aerodrome as well.

When Martin Provensen died of a heart attack in 1987 at age 70, Alice faced a crossroads, unsure whether she would continue an illustration career on her own. In another PW interview, from 2005, Provensen shared how she moved forward, finding strength to create such solo projects as The Buck Stops Here: The Presidents of the United States (Harper, 1990; revised 2011), A Day in the Life of Murphy (Simon Schuster, 2003) and Klondike Gold (Simon Schuster, 2005). “After Martin died, at first I didn’t think I would ever be able to work again,” she said. “But an editor I have known for a long time, Linda Zuckerman, nagged me and persuaded me to try new books. She has been an inspiration and a very good friend. Working on books, I’m not ever really alone. I always feel as though Martin is looking over my shoulder, telling me what I should do over—and letting me know what work is good.”

Linda Zuckerman, now an independent editorial consultant, shared her recollection of how her illustrator and friend found her way back to the art studio. “Alice was one of the most brilliant people I have ever known and I always felt honored to be her editor. I had worked with Alice and Martin on The Glorious Flight and other books and had visited their beautiful farm in upstate New York many times. After Martin died, suddenly and unexpectedly, I took the Metro North train to visit her. She was bereft. Martin had been not only her husband, but her artistic partner; they had worked together on many dozens of books beginning in the 1950s. It’s hard to imagine the degree of profound loss she must have felt.

I thought a lot about her on the trip home and many months after, and I remember feeling I had to do something to help. She needed to be working again. So on one visit I asked her how she’d feel about trying a book on her own. At first she said no, but I persisted as gently as I could. Then at one point she told me she had two ideas for a new picture book: one would be about fox-hunting, the other about the U.S. presidents. The result was The Buck Stops Here.

I know Alice has always credited me for getting her back to work, but she couldn’t have known the enormous satisfaction I felt on seeing the bound books of The Buck Stops Here for the first time. I learned a lot from her and I will miss her.”